Synopsis Speed Racer (Emile Hirsch) is an 18-year-old whose life and love has always been racing. As a young boy, Speed shirked his schoolwork, only dreaming of being able to race one day as well as his older brother, Rex Racer (Scott Porter).However, Rex eventually had an altercation with his father Pops Racer (John Goodman), and never returned home. In the 2-3 years of racing that Rex did, viewers were divided, calling him both brave and a coward. However, it was during the final leg of the Casa Cristo road rally that Rex died in a fiery crash in the Maltese Ice Caves. After this event, Speed continued racing, with his lost Brother constantly on his mind.Now the prime driver for Racer Motors, Speed Racer is quickly sweeping the racing world with his skill, driving the "Mach 6" of his father's design, but remains interested only in the art of the race and the well-being of his family. Speed father is still adamant that Racer Motors continue to be an independent in a sport where almost everyone is owned by a large corporation.Shortly after Speed's most recent win, Mr. Royalton (Roger Allam), owner of conglomerate Royalton Industries, shows up at the family's doorstep. Inviting the Racer family to tour his company, Speed is somewhat impressed, yet a little apprehensive. Royalton gives Speed a week to consider his offer.Speed eventually returns to Royalton, and declines his offer, citing that racing is more of a family affair for him. Royalton then shows his true colors, revealing that top corporate interests(including himself) have been fixing races and cheating to gain profits for years. In retaliation for his refusal, Royalton promises that Speed will lose his next race that takes place in Fiji, and that Racer Motors will come under scrutiny as well (proof of the power that he holds, all his threats come to pass, leading to Speed's loss and the destruction of the Mach 6 racer).Shortly afterwards, the Racer family is visited by Inspector Detector (Benno Fürmann) and the mysterious Racer X (Matthew Fox). Both men are involved in trying to uncover the unscrupulous business dealings and cheating that have been plaqueing the WRL (World Racing League) competitions for many years. Their wild card is Taejo Togokhan (Rain), the son of the owner of Togokhan Racing. Taejo has information that could incriminate Royalton, but will only divulge this if he is able to win the Casa Cristo cross-country race, also know as "The Crucible." The inspector knows the proposition is dangerous (Rex Racer was killed in a previous race), but hopes that Speed and Pops will reconsider, given that the Racer family is one of the last groups that is not tied to corruption. Pops angrily declines the offer, but Speed takes it into consideration, knowing the kind of power that Royalton can use to hurt his family. Trixie volunteers to help Speed, taking the Mach 5 under the guise that they are going skiing.Before the start of the race, a team working under the Inspector modifies the Mach 5 to counter any defensive measures other drivers will take. The first leg of the rally tests Speed, Racer x, and Taejo, with the three of them coming in behind Snake Oiler and his team.Speed and Trixie then receive a surprise when they find the entire Racer family has arrived, having seen Speed on television. Pops demands Speed drop out and come home, but Speed is adamant about winning the race, still thinking of his family's safety and what Taejo's information could do to help them.The family then decides to stay, and have Speed see the race through to the end. However, during the night, several ninjas are sent in to try and deal a blow to the racing team. Racer X handles one, while Pops takes care of another. However, Taejo has ended up being drugged, and is in no condition to race.A trade-off is made, wherein Trixie dresses up as Taejo to take his place until half-way through the race. Once they've reached a certain point, Taejo takes back the wheel to his vehicle, and the team continues to take on Snake Oiler and his team. Finally pulling ahead, the Togokhan roars to the finish.However, in the aftermath, it becomes apparent that Taejo's actions were mainly to affect his Father's stock price, and his deal to reveal secrets about Royalton falls through. Back home, Speed angrily drives the Mach 5 to the nearest track to get over his anger. It is here that he encounters Racer X, who races Speed, and is impressed by his skills.Speed finally asks a burning question that has been on his mind: Is Racer X his older brother, Rex? The clues seem to match up: Racer X appeared shortly after Rex was killed, and his driving style seems eerily similar. Racer X then reveals his identity to Speed, and the young man sees that the mysterious driver does not resemble his brother at all. Speed laments that their efforts at the Casa Cristo were for naught, but Racer X tries to help Speed see the silver lining in the situation.Back at home, Pops and Speed have a heart-to-heart, and Pops laments how he drove Rex away all those years ago, and how he felt in danger of doing the same thing when he attempted to deny Speed the chance to finish the Casa Cristo. Speed understands Pops' concern, but the moment is interrupted by the arrival of Taejo's sister, Horuko (Yu Nan). Horuko expresses regret for her Brother and Father's actions, and presents Speed with an invitation to the big Grand Prix race coming up. Taejo was planning not to enter anyway, but the rules also state that any member of the winning team can use the invitation and race.Reinvigorated, the Racer family and Trixie work round the clock and rebuild the Mach 6. Showing up just before the start of the race, Royalton is incensed over Speed's entry, and a number of drivers are informed to take Speed out during the race at all costs.Speed manages to dodge almost everything thrown at him, but runs into trouble when going up against Royalton's famed racer, Cannonball Taylor (Ralph Herforth). Taylor uses a secret weapon called a 'spear-hook,' almost causing Speed to wipeout. At the last second, Speed manages to send the two flying, with the illegal item being caught by the race cameras. As the two cars crash to the ground, Royalton's racer is dislodged and crashes.Speed has other problems when the Mach 6 refuses to start. After concentrating, and realizing just what his racer needs, Speed manages to get the vehicle started, and takes off, leading to an unstoppable finish and a surprise upset against Royalton and the other racers.Inspector Detector watches the celebration with Racer X. When the Inspector asks if X would like to be with the family, we realize (through flashbacks) that Speed was correct about Racer X. Rex Racer actually faked his death, and through plastic surgery, changed his identity to protect his family, as well as try and stop the corruption in racing with the inspector.In the aftermath of Speed's win, Taejo reveals Royalton's secrets, and the Corporate head is jailed, with the judge delivering the caveat, "Cheaters Never Win."